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Google Guava Preconditions are quite useful for validating arguments of methods. Here it is an example: public void setAge(int age) { Preconditions.checkArgument(assert age = 0, “Age cannot be negative”); …}
See how to use an extension method in C# to update all items in a list. public static IEnumerable ForEach(this IEnumerable collection, Action action){//Loop thru the collectionforeach (T item in
We can check if a given port is free by trying to construct a ServerSocket with the port that needs to be checked: import java.io.*;import java.net.*;public class CheckingIfPortIsFree{ public static
Get a list of the names of all normalization forms in SQL. 1NF 2NF 3NF BCNF Boyce-Codd Normal Form 4NF 5NF ONF: Optimal Normal Form DKNF: Domain-Key Normal Form
A zip file is a compressed file that can hold one or more files. The following code snippet lets us scan the contents of a given zip file. Code snippet:
Adding Log4j2 in a Spring Boot application can be done in two steps. For Maven, in pom.xml, exclude Spring Boot’s default logging: org.springframework.boot spring-boot-starter org.springframework.boot spring-boot-starter-logging Further, add Log4j2 dependency:
See how to reverse a string. public static string ReverseString( string input) { char[] array = input.ToCharArray(); Array.Reverse(array); return new string(array); }Console.WriteLine(ReverseString(“devx”));
ArrayList has an overloaded method that accepts a string, as well as an Integer, as an argument. The remove method can remove elements based on the string, along with the
Recently we experienced an interesting production problem. This application was running on multiple AWS EC2 instances behind Elastic Load Balancer. Application was running on GNU/Linux OS, Java 8, Tomcat 8 application server. All of sudden one of the application instances became unresponsive. All other application instances were handling the traffic properly. Whenever HTTP request was sent to this application instance from the browser, we were getting following response to be printed on the browser. Related Articles Troubleshooting Timeout in AWS Elastic Beanstalk Apache Unleashes New Tomcat Open Source Web Server Embedded Jetty and Spring: The Lightweight Antidote for Java EE Complexity
What can cause poor performance of a query? Any or a combination of these: No indexes exist for the tables Unnecessarily complicated joins Excess usage of cursors Excess usage of
The Hijri calendar system is somewhat different from the Gregorian calendar. This example does not discuss the complete Hijri calendar. This is only to educate you regarding the existence of
The Hijri calendar system is somewhat different from the Gregorian calendar. This example does not discuss the complete Hijri calendar. This is only to educate you regarding the existence of
Spring Data provide a class named RepositoryFactorySupport. Via this class we can access any repository, as in the following example: RepositoryFactorySupport factory = … // code that instantiate the factory;CustomerRepository
Use the CultureInfo class to format values based on a culture. See below for an example: public static void Main() { decimal inputValue = 233; CultureInfo currentCulture = new CultureInfo(“en-US”);
Moving away from the age old way of fixed arguments, Java supports variable arguments. The code sample below illustrates variable arguments. If the method has multiple arguments, it is mandatory
What types of indexes are there? Answer: Clustered Sort and store data based on key values Non-clustered Each key is a pointer to the data row
Java has a very powerful library for REGEX. A very basic usage of REGEX is being presented in the code snippet below and we can improve on this to develop
For disabling OSIV, we need to set up spring.jpa.open-in-view in application.properties as follows: spring.jpa.open-in-view=false
See how to use this function in C# to discover how many more days are left in a given countdown. DateTime startDate = DateTime.Now;DateTime endDate = DateTime.Now.AddDays(-1);TimeSpan t = startDate
MySQL supports AUTO_INCREMENT column types where the value of a particular column can be auto incremented as, and when, the records are inserted. Many instances would need the last value
The query below uses TOP to select the TOP 3 students: TOPSELECT TOP 3 *FROM Students; The code below uses LIMIT to only show three records: SELECT StudentName, StudentPercentageFROM StudentsLIMIT
StringWriter is similar to StringBuffer, which can collect a host of string values and work with the data. We will explore writing a porting of a given string. Code sample:
In Java, we can divide two positive integers and round up as follows: int result = (x + y – 1) / y Example: (4/3 = 1.33 and we want
Please see below for an example of how to convert a date time to ISO 8601 format. string isoFormatDateString = dateTimeObject.ToUniversalTime().ToString(“s”) + “Z”;
MySQL has abundant functions that support a multitude of application needs. Here, we shall use some Calendar functionality to find in which week a given date belongs. Samples: Considering the
Repository queries can be executed asynchronously using @Async annotation. The result can be a Future, CompletableFuture and ListenableFuture. The method will return immediately upon invocation: @asyncFuture findByName(String name);@asyncCompletableFuture findByName(String name);@asyncListenableFuture
There are many instances in which you might repeatedly use some functionality. It would be handy if you were allowed to create a function that could be used as, and
Avoid prefixing your Stored Procedure names with sp_. SQL Server first checks in the master database even when the Schema name is provided.
Avoid prefixing your Stored Procedure names with sp_. SQL Server first checks in the master database even when the Schema name is provided. ? Visit the DevX Tip Bank ?
A proof of concept can be seen below: @GetMapping(“…”)public MappingJacksonValue fooMethod(…) throws JsonProcessingException { List foos = …; MappingJacksonValue wrapper = new MappingJacksonValue(fooa); … return wrapper;}
